The present invention relates generally to industrial process transmitters. More particularly, the present invention relates to a visual display on a process transmitter.
Industrial process transmitters couple to industrial process equipment and/or conduits and are adapted to measure process parameters, such as pressure, mass flow rate, volume flow rate, temperature, and the like. Frequently, such transmitters draw power from a two-wire loop that carries an energy limited loop current, which varies within a range of 4-20 mA.
In some configurations, transmitters can utilize primary and secondary process measurements, using multiple sensors or field devices. For example, to calculate a mass flow measurement of gas or steam through a pipe, a flowmeter can be used to measure the volume flow rate, and a second sensor can be used to measure the line pressure.
The transmitter typically sends a signal related to a value of the process variable to a remote location such as a control room. Some transmitters also display a readout of the value of the process variable or other information on a panel of the transmitter housing. Advancements in transmitters have included a digital readout of the actual value of the process variable on a liquid crystal display (LCD) in the transmitter housing.